1. Integumentary System @ a GLANCE
Functions of Integumentary System
Two-way protective barrier
Temperature regulation
Houses sensory receptors
Secretes important fluids- sweat & oil
Organs of Integumentary System
Skin
Accessory Organs
Hair
Nails
Sebaceous glands
Sudoriferous glands

2. Medical Terminology: A Living Language, Fourth Edition
Bonnie F. Fremgen and Suzanne S. Frucht
Copyright ©2009 by Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
All rights reserved.
Figure 3.1 – Skin structure, including the three layers of the skin and the accessory organs: sweat glands, sebaceous glands, and hair.

3. Anatomy and Physiology
Largest organ in body
Weighs more than 20 pounds (in adult)
Skin also called:
Integument
Cutaneous membrane

4. 1. Protection Primary function Forms 2-way barrier
Protects underlying tissues
Forms 2-way barrier
Keeps out pathogens and harmful substances & prevents them from entering the body
Keeps in critical body fluids & prevents them from escaping the body

5. 2. Temperature Regulation
To cool skin:
Sweat evaporation
Dilate superficial blood vessels to release heat
To conserve heat:
Constrict superficial blood vessels to keep warm blood away from surface
Continuous fat layer acts as insulation

6. 3. Sensory Receptors Located within dermis Detects:
Temperature
Pain
Touch
Pressure
Nerve endings convey messages to brain and spinal cord

7. 4. Fluids Produced Sudoriferous (sweat) glands:
Assist body in maintaining homeostasis
Create cooling effect when sweat evaporates
Sebaceous (oil) glands:
Oil glands
Produce sebum
Lubricates the skin surface

8. The Skin Three layers Epidermis – thin, outer membrane layer
Dermis – middle, fibrous connective tissue layer
Subcutaneous layer – innermost layer of adipose

9. Epidermis Composed of stratified squamous epithelium
Flat scale-like cells
Arranged in overlapping layers called strata
Has no blood supply or connective tissue
Depends on deeper layers of skin for nourishment
Basal layer the deepest layer

10. Basal Layer of Epidermis
Cells continuously grow and push old cells toward surface
During this process
Cells shrink, die, and fill with hard protein called keratin
Keratinized cells allow skin to act as barrier to infection
Melanocytes
Special cells of basal layer
Produce black pigment melanin
Gives skin color
Protects against ultraviolet rays of sun

11. Dermis Also called corium
Located between epidermis and subcutaneous layer
Name means “true skin”
Is living tissue with very good blood supply

12. Dermis Composed of: Houses: Connective tissue and collagen fibers
Strong fibrous proteins give dermis flexible strength
Houses:
Hair follicles
Sweat glands
Sebaceous glands
Blood vessels
Lymph vessels
Sensory receptors
Nerve fibers
Muscle fibers

13. Subcutaneous Layer Also called hypodermis Third and deepest layer
Composed of fat cells called lipocytes
Protects the deeper tissues of body
Acts as insulation for heat and cold

14. Accessory Organs Located within dermis Include: Hair Nails
Sudoriferous (Sweat) glands
Sebaceous (oil) glands

15. Hair
Hair follicle
Hair root
Hair shaft
Arrector pili muscle

16. Hair Grows longer from the root Melanin gives hair its color
Deep cells of hair root force older cells to move upward
This forms hair shaft
Grows towards surface within hair follicle
Melanin gives hair its color
Arrector pili
Slip of smooth muscle
Causes hairs to “stand up”

17. Figure 3.3 – Structure of a hair and its associated sebaceous gland.
Medical Terminology: A Living Language, Fourth Edition
Bonnie F. Fremgen and Suzanne S. Frucht
Copyright ©2009 by Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
All rights reserved.
Figure 3.3 – Structure of a hair and its associated sebaceous gland.

18. Sebaceous Glands Lubricates hair and skin Prevents drying and cracking
Open into hair follicles
Secrete the oil sebum
Lubricates hair and skin
Prevents drying and cracking

19. Sweat Glands Also called sudoriferous glands Coiled gland in dermis
Sweat travels to surface in sweat duct
Sweat pore – surface opening

20. Sweat Glands 2 million throughout body Sweat or perspiration
Cools body as evaporates
Contains small amount of waste product
Normal colorless and odorless
Apocrine glands
Found in pubic and underarm areas
Thicker sweat that can produce an odor

21. Nails Nail body Nail bed Lunula Flat plate of keratin
Connects nail body to underlying tissue
Lunula
Half-moon white area at base of nail

22. Nails Grow longer from nail root Cuticle Free edge
Soft tissue that covers nail root
Free edge
Exposed edge

23. Figure 3.4 – External and internal structures of nails.
Medical Terminology: A Living Language, Fourth Edition
Bonnie F. Fremgen and Suzanne S. Frucht
Copyright ©2009 by Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
All rights reserved.
Figure 3.4 – External and internal structures of nails.

24. Medical Terminology: A Living Language, Fourth Edition
Bonnie F. Fremgen and Suzanne S. Frucht
Copyright ©2009 by Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
All rights reserved.
Figure 3.12 – Rule of Nines. A method for determining percentage of body burned. Each differently colored section represents 9% of the body surface.

25. First Degree Burn First degree burn
skin reddened and painful; no blisters; damage to epidermis

26. Second Degree Burn Second degree burn
skin reddened and painful with blisters; damage to epidermis and dermis

27. Third Degree Burn
Third degree burn
skin charred; epidermis and dermis burned away; subcutaneous layer exposed

28. Click here to view an interactive exercise on skin anatomy.
Skin Anatomy Exercise
Click here to view an interactive exercise on skin anatomy.
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29. Medical Terminology: A Living Language, Fourth Edition
Bonnie F. Fremgen and Suzanne S. Frucht
Copyright ©2009 by Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
All rights reserved.
Figure 3.5 – A cyanotic infant. Note the bluish tinge to the skin around the lips, chin, and nose. (St. Bartholomew's Hospital, London/Photo Researchers, Inc.)

30. Medical Terminology: A Living Language, Fourth Edition
Bonnie F. Fremgen and Suzanne S. Frucht
Copyright ©2009 by Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
All rights reserved.
Figure 3.6C – Purpura, hemorrhaging into the skin due to fragile blood vessels.

31. Medical Terminology: A Living Language, Fourth Edition
Bonnie F. Fremgen and Suzanne S. Frucht
Copyright ©2009 by Pearson Education, Inc.
Upper Saddle River, New Jersey 07458
All rights reserved.
Figure 3.8 – Strawberry hemangioma, a birthmark caused by a collection of blood vessels in the skin. (H.C. Robinson/Science Photo Library/Photo Researchers, Inc.)